Rechargeable battery packs and related methods

ABSTRACT

In one embodiment, a rechargeable battery pack can be configured to power an electronic device having a first battery. The rechargeable battery pack can comprise a second battery supplemental to the first battery, an external power input configured to couple to an external power source, a power output for powering the electronic device. The rechargeable battery pack can also comprise a first circuit comprising a first power path between the external power input and the power output, a second power path between the second battery and the power output, and a power switch set. When the external power source is decoupled from the external power input, the first power path is disabled by the power switch set, and the second power path is enabled by the power switch set. When the external power source is coupled to the external power input, the first power path is enabled by the power switch set, and the second power path is disabled by the power switch set. Other examples and embodiments are described herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to, and the benefit of, U.S.Provisional Application Ser. No. 60/612,770 filed Sep. 15, 2004, andtitled “Power Supply System Comprising Rechargeable Battery Pack andAttachment Apparatus,” which is hereby incorporated by reference.

This application is a continuation application of U.S. Utility patentapplication Ser. No. 11/228,666, filed Sep. 15, 2005, and titled “PowerSupply System Comprising Rechargeable Battery Pack And AttachmentApparatus,” which is hereby incorporated by reference.

TECHNICAL FIELD

This invention relates generally to accessories for portable electronicdevices, and relates more particularly to powering and attachmentaccessories for portable electronic devices.

BACKGROUND

Portable electronic devices are widely used, as are accessories for suchdevices that are designed to complement such devices or enhance theirutility. Among the available accessories are battery packs to providesupplemental power, attachment apparatuses that facilitate attachingcertain accessories to the portable electronic devices, and the like.

Various electronic devices are powered by a battery within the device.Such batteries provide a limited amount of power. Thus, a need exists,under certain circumstances, for supplemental sources of power. One suchsupplemental source of power, which has been used, is an external powersource such as an electrical power outlet that is typically notportable. However, electronic devices may not have access to poweroutlets at all times, and electronic devices may be used away fromexternal power sources such as power outlets for longer than thebatteries within the electronic devices are able to provide sufficientpower. Further, power outlets may have power outages. Thus, a needexists for supplemental battery power for electronic devices that areportable and reliable. If more than one source of power may be used, aneed exists for circuitry to control which source of power is used at aparticular time, based on, for example, the power sources that areavailable, the power demands of the electronic devices, the level ofcharge of the battery within the electronic device, and the like. Needsexist for power sources to be rechargeable, and for the user to be ableto determine the amount of charge that is present. Further, needs existfor sources of power and controls to be inexpensive, resistant todamage, and easy to use.

Specifically, some electronic devices that detect and identify externalaccessories do not do so dynamically. A single accessory that canperform the function of multiple accessories may perform better if theelectronic device could detect a change in accessory, although nophysical change has been made. Prior to this invention, physicalintervention by the user (such as moving a switch to a differentposition or physically re-attaching a different accessory) was thetypical way to enable a change in accessory. A scheme was needed, orwould be beneficial, that didn't require physical user intervention tooperate.

One method to force an electronic device to re-identify an accessory wasto electronically disconnect the accessory and re-connect after someperiod of time, forcing the electronic device to perform theidentification check again. Before reconnecting, the accessory mustchange the way that it electrically identifies itself. Several methodsexist for electrically disconnecting the accessory, a few examples ofthis would be: removing power from the electronic device, orelectrically removing a required accessory present signal. Electronicdevices have used a variety of methods to detect and identify externalaccessories. These methods can include resistors, resistor dividers,capacitors, and binary signals, just to name a few.

Further, apparatuses have been used that facilitate attachment of adevice to a portable electronic device having a battery. Suchapparatuses have been used that have an electrical connection to theelectronic device, which have included at least one plug with pins.However, forces applied to the plug have damaged the pins. Consequently,a need or potential benefit exists for an attachment apparatus shaped toprevent potentially harmful forces from being applied to a plug, or tolimit movement of a plug or electrical connection, for example, in amanner that protects the plug, electrical connection, or pins fromdamage.

Other needs and potential for improvement will be apparent from thisdisclosure or are know to those of skill in the art. Particularembodiments of the present invention may partially or completely fulfillone or more of these needs, or may provide other benefits which may ormay not be readily apparent.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood from a reading of the followingdetailed description, taken in conjunction with the accompanying figuresin the drawings in which:

FIG. 1 is a perspective view of a rechargeable battery pack according toan embodiment of the invention;

FIG. 2 is a perspective view of a different side of the rechargeablebattery pack of FIG. 1, viewed from a different angle;

FIG. 3 is a perspective view of an attachment apparatus capable ofattaching a first device to a portable electronic device having a firstbattery according to an embodiment of the invention;

FIG. 4 is a perspective view of a different side of the attachmentapparatus of FIG. 3, viewed from a different angle;

FIG. 5 is a perspective view showing the rechargeable battery pack ofFIGS. 1 and 2 attached to the attachment apparatus of FIGS. 3 and 4,according to an embodiment of the invention;

FIG. 6 is a circuit diagram of the block diagram in FIG. 11, accordingto an embodiment of the invention;

FIGS. 7 a, 7 b, and 7 c are circuit diagrams illustrating a circuitcapable of dynamically switching an electronic device between a firststate and a second state depending on a status of the rechargeablebattery pack of FIGS. 1 and 2 according to an embodiment of theinvention;

FIG. 8 is a circuit diagram showing a boost supply circuit according toan embodiment of the invention;

FIG. 9 is a circuit diagram illustrating an LED gas gauge circuitaccording to an embodiment of the invention;

FIG. 10 is a diagram illustrating connections to a connector of theelectronic device, to a battery terminal, and to a DC input jack on therechargeable battery pack of FIG. 1, according to an embodiment of theinvention;

FIG. 11 is a flow chart illustrating a method of making and marketing abattery pack according to an embodiment of the invention;

FIG. 12 is a block diagram illustrating a circuit capable of setting anddynamically changing a charge current supplied to a battery inside abody of the rechargeable battery pack of FIGS. 1 and 2, according to anembodiment of the invention; and

FIG. 13 is a block diagram illustrating a circuit capable of dynamicallyswitching the second battery between a first state and a second state,according to an embodiment of the invention.

For simplicity and clarity of illustration, the drawing figuresillustrate the general manner of construction, and descriptions anddetails of well-known features and techniques may be omitted to avoidunnecessarily obscuring the invention. Additionally, elements in thedrawing figures are not necessarily drawn to scale. For example, thedimensions of some of the elements in the figures may be exaggeratedrelative to other elements to help improve understanding of embodimentsof the present invention. The same reference numerals in differentfigures denote the same elements.

The terms “first,” “second,” “third,” “fourth,” and the like in thedescription and in the claims, if any, are used for distinguishingbetween similar elements and not necessarily for describing a particularsequential or chronological order. It is to be understood that the termsso used are interchangeable under appropriate circumstances such thatthe embodiments of the invention described herein are, for example,capable of operation in sequences other than those illustrated orotherwise described herein. Furthermore, the terms “comprise,”“include,” “have,” and any variations thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements is not necessarily limitedto those elements, but may include other elements not expressly listedor inherent to such process, method, article, or apparatus.

The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,”“under,” and the like in the description and in the claims, if any, areused for descriptive purposes and not necessarily for describingpermanent relative positions. It is to be understood that the terms soused are interchangeable under appropriate circumstances such that theembodiments of the invention described herein are, for example, capableof operation in other orientations than those illustrated or otherwisedescribed herein. The term “coupled,” as used herein, is defined asdirectly or indirectly connected in an electrical, mechanical, or othermanner.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Various embodiments of the present invention include a rechargeablebattery pack capable of providing electric power to an electronic devicehaving a first battery. In several embodiments the rechargeable batterypack has a body with a second battery inside for storing electricalenergy. In some embodiments, the rechargeable battery pack may have acircuit inside the body capable of dynamically changing a charge currentsupplied from an external power source to the second battery based on apower consumption level of the electronic device. In some embodiments,the battery pack may include a circuit inside the body configured to:(1) power the electronic device with the second battery when therechargeable battery pack is electrically coupled to the electronicdevice and when electrically decoupled from the external power source;and (2) power the electronic device with the external power source whenthe rechargeable battery pack is electrically coupled to the externalpower source and the electronic device. In some embodiments, therechargeable battery pack may have a charge level indicator, examples ofwhich are described in more detail below.

Further, some embodiments of the invention may include an attachmentapparatus for attaching the rechargeable battery pack to the electronicdevice. As an example, the attachment apparatus may comprise a frame, anextension protruding from the frame, and a number of attachment featuressuitable for working with the recesses to attach the battery pack andthe attachment apparatus to each other and to the electronic device.Such an attachment apparatus may include a number of sides, some ofwhich may have openings, and the attachment apparatus may further havean extension protruding from one side. This extension may surround orsubstantially surround an opening in the side, and may protect adisconnectable electrical connection of the rechargeable battery packthat fits inside the extension. Some embodiments of the inventioninclude a combination of these features or one or more of these featuresin combination with other features described herein.

In one particular embodiment of the invention, a power supply systemcapable of providing electric power to an electronic device having afirst battery comprises a battery pack and an attachment apparatus. Thebattery pack comprises a body having a number of recesses, a secondbattery inside the body, and at least one of: (1) a first circuitcapable of dynamically changing a magnitude of a charge current suppliedto the second battery based on a power consumption level of theelectronic device; and (2) a second circuit capable of dynamicallyswitching the second battery, depending on a status of the battery pack,between: (a) a state in which the second battery is not being drained,i.e., is not being used as a power source; and (b) a state in which thesecond battery is being drained, i.e., is being used as a power source.The state described in (a) will be referred to herein as a first state,and the state described in (b) will be referred to herein as a secondstate. In this embodiment, when the battery pack is electrically coupledto the electronic device, the electronic device will draw power from thesecond battery in the battery pack and will not draw power from thefirst battery in the electronic device until after the second battery isdepleted.

As used herein, the term “dynamically” means automatically and insubstantially real time. In other words, “dynamically” meansaccomplished in response to one or more changing variables (other thantime) without human interaction, and without a significant delay.“Dynamically” does not include actions that are initiated by humaninteraction or actions that occur at one or more timed intervals. Alsoas used herein, the term “state”, as applied to a battery, may indicatewhether (or not) the battery is being drained. As an example, the firststate of the second battery may be a state in which the second batteryis not being drained, i.e., is not being used as a power source, and thesecond state may be a state in which the second battery is beingdrained, i.e., is being used as a power source.

Further, as used herein, the “status” of a battery pack may includewhether the battery pack is electrically coupled to an external powersource. For instance, the status of a battery pack can be one of a firstcondition when the battery pack is electrically coupled to an externalpower source such as a wall outlet, or the status of a battery pack canbe a second condition when the battery pack is electrically decoupled tothe external power source. In some embodiments where the battery pack iselectrically coupled to the electronic device, for example, the secondcircuit may automatically and dynamically switch the second battery tothe first state (i.e., not used as a power source) when, after, or whilethe status of the battery pack is changed from the second condition tothe first condition (i.e., coupled to the external power source), andthe second circuit may automatically and dynamically switch the secondbattery to the second state (i.e., used as a power source) when, after,or while the status of the battery pack is changed from the firstcondition to the second condition (i.e., decoupled from the externalpower source).

As mentioned, various embodiments of the invention may include anattachment apparatus. In some embodiments, the attachment apparatuscomprises a frame, an opening in the frame, and an extension adjacent tothe opening. In some particular embodiments of the attachment apparatus,the extension protrudes from the frame. Further, in some embodiments,and the attachment apparatus includes a number of attachment featuressuitable for working with or engaging recesses in the body of thebattery pack to attach the battery pack and the attachment apparatus toeach other and to the electronic device.

Additional embodiments of the invention include methods of manufacturingthe devices described herein, which include providing variouscombinations of components described in this document or know in theart. Other embodiments of the invention also include methods of usingthe devices described herein. Certain embodiments of the invention alsoinclude various combinations of functions, including those describedherein, and particular combinations of functions and structure.

Referring now to the figures, FIGS. 1 and 2 are perspective views of arechargeable battery pack 100 capable of providing electric power to anelectronic device (not shown) having a first battery (not shown),according to an example of an embodiment of the invention. Asillustrated in FIGS. 1 and 2, rechargeable battery pack 100 comprises abody 110, and body 110 comprises a surface 112, a surface 113, a surface115, a surface 211, a surface 214, and a surface 216. In the embodimentillustrated, surface 112 is located opposite surface 211, and issubstantially parallel thereto. Surface 113 extends between and issubstantially perpendicular to surfaces 112 and 211. Surface 214 islocated opposite and is substantially parallel to surface 113. Surface115 extends between surfaces 211 and 112, extends between surfaces 113and 214, and is substantially perpendicular to each of those surfaces.Finally, surface 216 is located opposite and is substantially parallelto surface 115. In other words, as can be seen in the figures, in thisparticular embodiment, body 110 forms a rectangular box, with surfaces115 and 216 having substantially more area than the other four surfaces.It is possible that in another embodiment, body 110 could have someother configuration. Body 110 can be formed of a polycarbonate material,or of a material that is a blend of polycarbonate and acrylonatrilebutadeine styrine (ABS), as examples.

In the embodiment illustrated, Surface 211 comprises a recess 221 and arecess 222. Although they are not visible in the figures, surface 112comprises its own recesses that are analogous to recess 221 and 222.Similarly, surface 113 comprises a recess 121, and surface 214 comprisesa recess 223. As further discussed below, in the particular embodimentillustrated, these recesses are used when rechargeable battery pack 100is attached to the attachment apparatus mentioned above, whichattachment apparatus facilitates the attachment of rechargeable batterypack 100 to an electronic device, as will also be further discussedbelow.

Still referring to FIGS. 1 and 2, in the embodiment illustrated, body110 further comprises a charge level indicator 130, comprising anactuator button 131, a light pipe 132, and, not explicitly illustratedin the figures, first and second light sources inside body 110. In aparticular embodiment, the first light source emits a green light whenilluminated, and the second light source emits a red light whenilluminated. Accordingly, in the description that follows, the firstlight source will also be referred to as a green light source, and thesecond light source will also be referred to as a red light source. Itshould be understood, however, that different embodiments ofrechargeable battery pack 100 may use colors different from those thatare described here. In this particular embodiment, both light sourcesare visible through light pipe 132. Thus, if both light sources areilluminated at the same time, the light from both light sources issimultaneously visible through light pipe 132.

In one embodiment, actuator button 131 is of the push-button variety,and is actuated by a physical press and release. In another embodiment,actuator button 131 can be an electrostatic device that is actuated by atouch rather than a physical movement of actuator button 131 itself.Additional mechanical or non-mechanical actuator button styles may beused in some embodiments. Charge level indicator 130 may include acircuit, and actuator button 131 may be part of that circuit. Chargelevel indicator 130 or the circuit therefore may be referred to as a“gas gauge.” An example of a charge level indicator circuit or gas gaugeis illustrated in FIG. 9 and described below with reference thereto.

Still referring to FIGS. 1 and 2, various embodiments of the inventionmay include part or all of a disconnectable electrical connection, forexample, between a battery pack and an electrical device. In theembodiment illustrated in FIGS. 1 and 2, rechargeable battery pack 100comprises an electric cable 230, and a dock connector 240. Dockconnector 240 or part thereof is an example of an electrical connectionbetween battery pack 100 and another device. Dock connector 240 may becapable of being electrically coupled to the electronic device, thusproviding an electrical connection between the electronic device andrechargeable battery pack 100 or another device. In some embodiments,electric cable 230 and dock connector 240 conducts electric signals,transmits electrical power, or both (sequentially and/orsimultaneously), between the electronic device and a second batterywithin rechargeable battery pack 100.

In many embodiments, rechargeable battery pack 100 still furthercomprises a second battery (not shown) inside body 110. In variousembodiments of the invention, body 110 may also contain one or morecircuits, examples of which are described below with reference to FIGS.6-13, but first, examples of an attachment apparatus in accordance withthe present invention will be described.

Illustrating a specific example of the invention, FIGS. 3 and 4 areperspective views of an attachment apparatus 300 capable of attaching afirst device to a portable electronic device (not shown) having a firstbattery (not shown). The portable electronic device may be similar towhat has been referred to above as the electronic device, and the firstbattery may be the same as or similar to what was referred to above asthe first battery. The first device can be a battery pack, a speaker, oranother hardware device, a memory device, a mounting accessory, or thelike. In a particular embodiment, the first device is rechargeablebattery pack 100 from FIGS. 1 and 2. The portable electronic device canbe a device that is configured to play audio recordings, such as an MP3player, a CD player, a digital camera, a pocket PC (personal computer),a cellular telephone, or the like. In some embodiments, attachmentapparatus 300 may attach to the first device and the electronic device,and may hold them in a particular orientation relative to each other.

As illustrated in FIGS. 3 and 4, for the purpose of describing anexample of the invention, attachment apparatus 300 comprises a hollowframe 310 comprising a side 311, a side 312 opposite and substantiallyparallel to side 311, a side 313 extending between and substantiallyperpendicular to the side 311 and side 312, a side 314 opposite andsubstantially parallel to side 313, a side 315 extending between andsubstantially perpendicular to side 311 and side 312, and furtherextending between and substantially perpendicular to the side 313 andside 314, and a side 316 opposite and substantially parallel to side315. In this particular embodiment, side 314 defines an opening 420,side 315 defines an opening 330, and side 316 defines an opening 440.Opening 330 receives the portable electronic device, and opening 440receives the first device.

In some embodiments, including the one illustrated, attachment apparatus300 further comprises an extension 350 protruding from side 314, andrails 451 and 452 adjacent to an opposite side of opening 440. Extension350 at least partially surrounds opening 420, and may serve to protectand prevent damage to an item inserted through extension 350 and opening420. Such an item may be, for example, a power cord, which may include adisconnectable electrical connection between the battery pack and theelectronic device. Dock connector 240 described herein with reference toFIG. 2 is one example of such a connection. Such an electricalconnection may fit inside extension 350. Extension 350 may serve toprotect and prevent damage to the portable electronic device, and inparticular, to a connector, such as a female connector, for instance, ofthe portable electronic device. In that regard, extension 350 prevents amating connector, such as a male connector, such as connector 240, frommoving from side to side. Accordingly, as an example, connector 240 maybe prevented from bending to the degree that the female connector orother component of the portable electronic device is damaged. In someembodiments, opening 420 has an oblong or elliptical shape, andextension 350 surrounds opening 420 on at least three sides. In someembodiments, extension 350 comprises a perimeter 351 having a gap 352therein. In various embodiments, gap 352 can extend along an entireheight 355 of extension 350, as illustrated in FIG. 3, or,alternatively, gap 352 can extend along only a portion of height 355.

In some embodiments, rail 451 comprises attachment features 461 and 462,and rail 452 comprises attachment features 463 and 464. The first devicemay fit between rails 451 and 452, and may be held in place byattachment features 461-664. In one embodiment, attachment feature 461comprises a lip or protrusion extending toward rail 452, and attachmentfeature 463 comprises a lip or protrusion extending toward rail 451.Attachment features 462 and 464 can be similar to, respectively,attachment features 461 and 463.

In some embodiments, attachment apparatus 300 still further comprises anattachment feature 471 and an attachment feature 472, both of which maybe adjacent to opening 440. In one embodiment, attachment feature 471and/or attachment feature 472 comprise a lip or protrusion extendinginto opening 440. In the illustrated embodiment, recesses 221, 222, 121,and 223 (FIGS. 1 and 2) receive, respectively, attachment features 463,464, 471, and 472. Attachment features 461 and 462 are received by therecesses on surface 112 (FIG. 1) that are not visible in the figures butthat are analogous to recesses 221 and 222.

Referring still to FIGS. 3 and 4, in the particular embodimentillustrated, side 313 comprises an opening 360, which exposes a firstportion of the portable electronic device when the portable electronicdevice is attached to or located within attachment apparatus 300. As anexample, opening 360 may allow access to a control, a port, or the likethat may be located at the first portion of the portable electronicdevice. Similarly, in the embodiment illustrated, side 311 comprises acutout 381, and side 312 comprises a cutout 382, both of which mayexpose a second portion of the portable electronic device when theportable electronic device is attached to attachment apparatus 300. Insome embodiments, cutouts 381 and 382 allow the portable electronicdevice to more easily be attached to and removed from attachmentapparatus 300.

FIG. 5 is a perspective view showing rechargeable battery pack 100attached to attachment apparatus 300, according to an embodiment of theinvention, thus forming a power supply system capable of providingelectric power to an electronic device such as or similar to thoseenumerated or referred to herein. Attachment apparatus 300 may be formedof a low-density polyethylene (LDPE), as an example, which may giveattachment apparatus 300 a clean and white translucent appearance, anon-tacky feel, and an appropriate degree of malleability, meaning it isflexible enough to bend to allow the first device and the portableelectronic device to be attached and detached, but still has enoughrigidity to allow the attachment features to perform or operateproperly.

In a particular embodiment, the electronic device is configured to playaudio recordings, such as an MP3 player, and may be an iPod™ devicemanufactured by Apple Computer, Inc. of Cupertino, Calif., for example.Different sizes or configurations of attachment apparatus 300 or frame310 may be provided for different size electronic devices or iPod™devices. A user may install battery pack 100 within attachment apparatus300, and then install the electronic device within attachment apparatus300, or vice versa. The electronic device, battery pack 100, or both,may be installed in attachment apparatus 300 by inserting one end first,and then the other end. For example, the bottom may be inserted first,then the top. The user may check that tabs are inserted into slots, asdescribed herein. The user may then plug dock connector 240 into theelectronic device, which may include sliding dock connector 240 withinextension 350.

Once connected with dock connector 240, the electronic device may runoff of battery pack 100 instead of the first battery, as long as thereis enough power in battery pack 100. Thus, battery pack 100 may extendthe amount of time that the electronic device will operate without beingcharged. In a particular embodiment, battery pack 100 allows theelectronic device (an iPod™ device in some embodiments) to play for anadditional 8 to 10 hours, for example. In embodiments so equipped, auser may check the amount of charge left in battery pack 100 by pressingactuator button 131 and viewing the color of light indicating thebattery status, for example, as described herein.

As mentioned above, in various embodiments of the invention, body 110,illustrated in one embodiment in FIG. 1, may also contain variouscircuits. Two examples of such circuits are: (a) a first circuit capableof dynamically changing a magnitude of a charge current supplied to thesecond battery from an external power source based on a powerconsumption level of the electronic device; and (b) a second circuitcapable of dynamically switching the second battery between a firststate and a second state depending on a status of the rechargeablebattery pack. Examples of both the first circuit and the second circuitwill be further described below.

Skipping forward to FIGS. 12 and 13, FIG. 12 illustrates a block diagramof a circuit 1200, which is an example of the first circuit, and FIG. 13illustrates a block diagram of a circuit 1300, which is an example ofthe second circuit. In FIG. 12, circuit 1200 may be capable ofdynamically changing a charge current supplied to a battery inside body110 of rechargeable battery pack 100 (FIGS. 1 and 2) according to anembodiment of the invention. Circuit 1200 is also capable of setting abattery charge current for the battery inside the body of therechargeable battery pack, according to an embodiment of the invention.The battery inside body 110 was introduced above, and will continue tobe referred to herein, as the second battery. In this particularembodiment, circuit 1200 dynamically changes the magnitude of the chargecurrent supplied to the second battery from an external power sourcebased on a power consumption level of an electronic device to whichrechargeable battery pack 100 is electrically coupled. Recall from abovethat the electronic device may have its own internal battery, introducedabove and referred to herein as the first battery. In particularembodiments of the present invention, the charge current charges thesecond battery in the manner described herein.

In some embodiments when rechargeable battery pack 100 is electricallycoupled to the electronic device and also to an external power source,circuit 1200 may facilitate a smooth integration between the electronicdevice and rechargeable battery pack 100 (FIG. 1) and may also permitthe external power source to efficiently charge the second battery whilesimultaneously operating the electronic device. In this manner, circuit1200 eliminates the need to completely charge the first battery of theelectronic device before charging the second battery. More specifically,circuit 1200 can route to the electronic device whatever current isneeded to operate the electronic device, and can route any extra current(i.e., the charge current) to rechargeable battery pack 100 for thecharging of the second battery. When the electronic device drawsrelatively less current, relatively more current may be available fromthe external power source to recharge the second battery via circuit1200, and when the electronic device draws relatively more current,relatively less current may be available from the external power sourcevia circuit 1200 to recharge the second battery. In some embodiments,when the external power source is coupled to battery pack 100, circuit1200, which is located within battery pack 100, may transmit the chargecurrent to the second battery even if the second battery is alreadyfully charged.

It should be understood that in some embodiments, the external powersource that is used to charge rechargeable battery pack 100 may havepre-determined power limits that, if exceeded, could cause damage to theexternal power source, to rechargeable battery pack 100, and/or to theelectronic device. By dynamically switching the charge current torechargeable battery pack 100, the electronic device can be chargednormally and remain unaffected by unexpected power fluctuations from theexternal power source.

As illustrated in FIG. 12, circuit 1200 comprises many elements,including a Vin input 1201, which is electrically coupled to an input ofa current sense subcircuit 1210 and an input of a charge current controlswitch subcircuit 1220. Subcircuit 1210 is electrically coupled toanother input of subcircuit 1220, and subcircuit 1210 has a Vout output1202, which is connected to an input of the electronic device whenrechargeable battery pack 100 (FIG. 1) is electrically coupled toelectronic device. A resistor 1241 is electrically coupled to an outputof subcircuit 1220 and to at least one input of a charge managementintegrated circuit (“IC”) or chip 1290. A resistor 1249 is electricallycoupled, at one end, between input 1201 and the input to subcircuit 1220and, at the other end, between resistor 1241 and the input of chip 1290.In this configuration, resistor 1249 is a feedback resistor forsubcircuit 1220. A Vin input 1203 is electrically coupled to at leastone other input of chip 1290. Chip 690 has a Vout output 1204, which iselectrically coupled to the second battery.

In one embodiment, chip 1290 is a two-cell charge management IC sold byTexas Instruments, Inc. of Dallas, Tex. under part number BQ24004. Inthis embodiment, resistors 1241 and 1249 are electrically coupled inparallel to pins 2, 3, 5 of chip 1290, and input 1203 is electricallycoupled to pins 4, 8, and 9 of chip 1290. In different embodiments,other battery charge management ICs may be used instead. Furthermore, inthe same or different embodiments, inputs 1201 and 1203 can be at thesame voltage potential.

Circuit 1200 is an example of a circuit that may dynamically change acharge current supplied from an external power source to a secondbattery based on a power consumption level of the electronic device. Inthe embodiment of circuit 1200 illustrated, current sense circuit 1210may detect or measure current to Vout 1202, for example, to theelectronic device. Based on what this current is, current sense circuit1210 may send a signal to current control switch 1220, for example,indicating whether to open or close. Current control switch 1220 mayclose so that current can flow through both resistor 1249 and resistor1241 in parallel, or switch 1220 may open, so that current can flow onlythrough resistor 1249 and not through resistor 1241.

In a particular embodiment, when rechargeable battery pack 100 isconnected to an external power source and the current draw of theelectronic device is high, switch 1220 is off (open). Thus, the chargecurrent going to the second battery is routed by circuit 1200 throughresistor 1249 only, thus increasing the voltage across this resistor anddecreasing the amperage or magnitude of the charge current. When thecurrent draw of the electronic device is low, switch 1220 is on (closed)in this embodiment, allowing more charge current to pass throughresistors 1241 and 1249 in parallel. Thus, the voltage across resistors1241 and 1249 is decreased and the amperage or magnitude of the chargecurrent is increased such that the second battery receives a greatercharge and takes a relatively shorter amount of time to fully charge. Insome embodiments, the second battery is being charged wheneverrechargeable battery pack 100 is connected to an external power source.Thus, the second battery may be charged in one of two states: either afast charge mode or a slow or low charge mode.

In some embodiments, chip 1290 may dynamically detect a change incurrent sense circuit 1210, for example, and may set the charge rate tofast or slow, for instance.

Turning to the next figure, FIG. 13 illustrates a block diagram ofcircuit 1300, which, as indicated earlier, is an example of the secondcircuit. Accordingly, circuit 1300 is capable of dynamically switchingthe second battery between a first state (where the second battery isnot being drained and is not being used as a power source by theelectronic device) and a second state (where the second battery is beingdrained and is being used as a power source by the electronic device).For instance, rechargeable battery pack 100 (FIG. 1) may be capable ofbeing electrically coupled to and decoupled from an external powersource, such as a power port on a computer or a wall outlet capable ofsupplying alternating current (AC), which may be reduced to a lowervoltage, converted to direct current (DC) or both. In a particularembodiment, circuit 1300 may be configured to facilitate powering theelectronic device with the second battery when rechargeable battery pack100 (FIG. 1) is electrically decoupled from the external power sourceand is electrically coupled to the electronic device. In this sameembodiment, circuit 1300 may be configured to facilitate powering theelectronic device with the external power source when rechargeablebattery pack 100 (FIG. 1) is electrically coupled to the external powersource and the electronic device. Thus, despite being electricallycoupled to the electronic device, the second battery may be in a stateof not being used as a power source when rechargeable battery pack 100(FIG. 1) is electrically coupled to the external power source.

Referring still to circuit 1300 in FIG. 13, in various embodiments, thesecond battery may be used as a power source when the second battery isin the second state, and the second battery may not be used as a powersource when the second battery is in the first state. The status ofrechargeable battery pack 100 (FIG. 1) may be one of: a first conditionin which rechargeable battery pack 100 is electrically coupled to theexternal power source; and a second condition in which rechargeablebattery pack 100 is electrically decoupled from the external powersource. In some embodiments where the rechargeable battery pack 100 iselectrically coupled to the electronic device, circuit 1300 places thesecond battery in the first state when rechargeable battery pack 100 isin the first condition, and circuit 1300 places the second battery inthe second state when rechargeable battery pack 100 is in the secondcondition.

In summary of the above, in a particular embodiment, when rechargeablebattery pack 100 is electrically coupled to the external power sourceand to the electronic device, circuits 1200 (FIG. 12) and 1300 (FIG. 13)cause the electronic device to charge its internal battery, which is thefirst battery, using a charge current that only exists when rechargeablebattery pack 100 is electrically coupled to the external power sourceand to the electronic device. On the other hand, when rechargeablebattery pack 100 is not electrically coupled to the external powersource, but is electrically coupled to the electronic device, circuits1200 (FIG. 12) and 1300 (FIG. 13) causes the electronic device to drawpower from the second battery. Thus, circuit 1200 can be used in acomplimentary manner with circuit 1300, and vice versa. Circuit 1200 maybe used to determine how quickly to recharge the second battery withinrechargeable battery pack 100 from an external power source, and circuit1300 may be used to determine whether or not to use the second batterywithin rechargeable battery pack 100 as a power source for theelectronic device. On the other hand, some embodiments of the inventionmay include just one of these circuits.

As illustrated in FIG. 13, circuit 1300 comprises many elements,including switches 1310 and 1330 and a filter 1320. Switch 1330 has an“identify control” input 1301 and an output 1390, which is coupled to anidentification input of the electronic device. A resistor 1340 can becoupled between a terminal of switch 1330 and a ground potential. Switch1330 can be used to notify the electronic device that rechargeablebattery pack 100 (FIG. 1) is electrically coupled to the electronicdevice. In one embodiment, input 1301 can be at the same voltagepotential as inputs 1201 and 1203 in FIG. 12.

Switches 1310 have a Vout input 1302 and a Boost Out input 1303. In oneembodiment of circuit 1300, a first one of switches 1310 has input 1302,and a second one of switches 1310 has input 1303. Input 1302 representsthe power input from the external power source, and input 1303represents the power input from the second battery of rechargeablebattery 100 (FIG. 1). A filter 1320 is electrically coupled betweenterminals of switches 1310 and a Vout input 1305. In one embodiment,input 1305 can be at the same voltage potential as input 1302. Switcheshave outputs 1304, which are electrically coupled to one or more inputsto the electronic device.

Skipping back to FIG. 6, FIG. 6 is a circuit diagram illustrating acircuit 600, which may be an embodiment of the block diagram circuit1200 in FIG. 12. As illustrated in FIG. 6, in this embodiment, circuit600 comprises an operational amplifier 610 having an inverting input611, a non-inverting input 612, and an output 613. Circuit 600 furthercomprises, in the embodiment illustrated, an inverter 620 having aterminal 621 electrically coupled to output 613, a power limiting switch630 having a terminal 631 electrically coupled to a terminal 622 ofinverter 620, and a resistor 641 electrically coupled to a terminal 632of power limiting switch 630. In some embodiments, power limiting switch630 dynamically directs a current in circuit 600 such that the currentin circuit 600 either travels through or bypasses resistor 641 based onthe power consumption level of the electronic device. In the embodimentshown, power limiting switch 630 comprises at least one transistor, suchas a field effect transistor having gate, source, and drain terminals.

Referring still to FIG. 6, in the embodiment illustrated, circuit 600further comprises a resistor 642 and a resistor 643 electrically coupledto inverting input 611, a resistor 644 and a resistor 645 electricallycoupled to non-inverting input 612, and a resistor 646 electricallycoupled to resistor 642 and to resistor 644. In this particularembodiment, circuit 600 still further comprises a resistor 647electrically coupled between output 613 and terminal 621 of inverter620, a capacitor 660 electrically coupled between resistor 647 andterminal 621 of inverter 620, a resistor 648 electrically coupled toterminal 631 of power limiting switch 630 and to a terminal 633 of powerlimiting switch 630, and a resistor 649 electrically coupled to resistor648 and to resistor 641. In some embodiments, resistors 642, 643, 644,645, and 646, as well as operational amplifier 610 may form a currentsense block. In a particular embodiment, resistor 642 has a resistanceof 10 K ohms, resistor 646 has a resistance of 0.22 ohms, resistor 644has a resistance of 200 ohms, resistor 643 has a resistance of 976 Kohms, resistor 645 has a resistance of 200 K ohms, resistor 647 has aresistance of 5.1 M ohms, resistor 648 has a resistance of 220 K ohms,resistor 641 has a resistance of 0.18 ohms, and resistor 649 has aresistance of 1.0 ohms, for example. In such an embodiment, capacitor660 may have a capacitance of 0.1 micro Farads.

In some embodiments, the current draw of the electronic device may bemeasured and fed into operational amplifier 610, which may turn powerlimiting switch 630 on or off depending on the magnitude of the currentdraw. In a particular embodiment, when rechargeable battery pack 100 isconnected to an external power source and the current draw of theelectronic device is high, power limiting switch 630 is off (open).Although rechargeable battery pack 100 may still be connected to anexternal power source, the charge current cannot pass through resistor641, and is limited to the current that flows through resistor 649,Thus, the voltage across resistor 649 is increased and the amperage ormagnitude of the charge current is decreased such that the secondbattery receives only a trickle charge and takes a relatively longeramount of time to fully charge. When the current draw of the electronicdevice is low, power limiting switch 630 is on (closed) in thisembodiment. Thus, the charge current going to the second battery isrouted by circuit 600 through resistor 641 and resistor 649 in parallel,thus decreasing the voltage across these resistors and increasing theamperage or magnitude of the charge current such that the second batterymay be fully charged in a relatively short amount of time. In someembodiments, the second battery is being charged whenever rechargeablebattery pack 100 is connected to an external power source. Thus, thesecond battery may be charged in one of two states: either a fast chargemode or a slow or low charge mode, as will be further explained below.

In an embodiment where the electronic device is a device that isconfigured to play audio recordings, such as an MP3 player, such as aniPod™ device manufactured by APPLE COMPUTER, as an example, resistor 641has a resistance of between approximately 0.15 and 0.25 ohms, and powerlimiting switch 630 is off when a voltage drop across resistor 646 isgreater than approximately 0.059 volts, and on when the voltage drop isless than that approximate value. Alternatively, a voltage drop of someother magnitude may be used, and the resistances of resistors 642, 643,644, and 645 may be altered from the values disclosed herein, and may beselected such that the output of the current sense block remainssubstantially unchanged.

The foregoing components of circuit 600 are, in some embodiments, partof a sub-circuit 601. Still referring to FIG. 6, circuit 600 may furthercomprise a sub-circuit 602, which may set the battery charge current forthe second battery. The power limiting capabilities of rechargeablebattery pack 100 may be facilitated by a chip 690 that may dynamicallydetect a change in the current-sense portion of circuit 600. In someembodiments, the current-sense portion of circuit 600 may set themagnitude of the charge current for chip 690. By sensing the currentsupplied to the electronic device, resistor 641 may be switched in andout, as described above, in order to change the magnitude of the batterycharge power supplied to the second battery. As mentioned above, in someembodiments, chip 690 sets the magnitude of the charge current, forexample, either to a fast charge mode or a low charge mode. As anexample, the fast charge mode may be enabled when the current throughresistor 646 is less than or equal to approximately 0.27 amps, which mayhappen when the electronic device is drawing relatively lesser amount ofcurrent. Continuing the example, the low charge mode may be enabled whenthe current through resistor 646 is greater than approximately 0.27amps, which may happen when the electronic device is drawing arelatively greater amount of current. In a particular embodiment, infast charge mode, Vcc_BAT+ coming out of chip 690, which is the chargecurrent for the second battery, is approximately equal to 0.55 amps,while in low charge mode Vcc_BAT+ is approximately equal to 0.1 amp. Ina particular embodiment, resistor 641 is connected to pins 2, 3, and 5of chip 690. The VCC_(—)9V may be connected to pins 4, 8, and 9 of chip690, and the VCC_BAT+ may be connected to pins 17, 18, and 19 of chip690.

FIGS. 7 a, 7 b, and 7 c illustrate an example of a second circuit whichmay be, for example, configured to power an electronic device with asecond battery when a rechargable battery pack is electrically decoupledfrom an external power source. In some embodiments, this second circuitmay be configured to power the electronic device with the external powersource when the rechargeable battery pack is electrically coupled to theexternal power source. The embodiment illustrated comprises sub circuitsillustrated in FIGS. 7 a, 7 b, and 7 c, which may be separate orinterconnected. Referring first to FIG. 7 b, in the particularembodiment illustrated, a transistor 710 having a terminal 711 iselectrically coupled to an input of the first battery, a transistor 720having a terminal 721 is electrically coupled to an output of the secondbattery, a third transistor 730 having a terminal 731 is electricallycoupled to the external power source, and a resistor 740 is electricallycoupled to a terminal 732 of transistor 730. Particular embodimentsinclude a capacitor 765 and a resistor 770 electrically coupled to aterminal 712 of transistor 710, and a diode 780 electrically coupled toa terminal 713 of transistor 710. Referring to FIG. 7 a, the embodimentillustrated further comprises a diode 750 electrically coupled to aterminal 722 of transistor 720, a capacitor 755 and a resistor 760electrically coupled to diode 750. Some embodiments may include one ormore filters, which may be RC filters, and may filter power supplied tothe electronic device. For instance, capacitor 755 and resistor 760 maybe a filter. Capacitor 765 and resistor 770 may also be a filter. Insome embodiments, a plurality of filters may form a filter block.

In one embodiment, diode 750 may be part number D8 BAT54C, capacitor 755may have a capacitance of 1 micro Farad, resistor 760 may have aresistance of 10 M ohms, and transistor 720 may have part number Q15ZXMP3A13F, for example. In a particular embodiment, capacitor 765 mayhave a capacitance of 1 micro Farad, diode 780 may be part number D2CMS04, resistor 770 may have a resistance of 5.1 M ohms, and transistor710 may be part number Q14 ZXMP3A13F, for instance. Resistor 740 mayhave a resistance of 255 K ohms, and transistor 730 may have part numberQ1 ZXMP3A13F, also as examples.

In the embodiment where the electronic device is a device that isconfigured to play audio recordings, such as an MP3 player, such as aniPod™ device manufactured by APPLE COMPUTER, for example, the externalpower source may be a FireWire port on a computer, and resistances ofresistors 740, 760, and 770 may be, respectively, between 200 and 300kilohms, between 9.5 and 10.5 megohms, and between 4.9 and 5.3 megohms.In the same embodiment, a capacitance of capacitor 755 and a capacitanceof capacitor 765 may both be between 0.5 and 2.0 microfarads. In thesame or another embodiment, diode 750 may be a Schottky diode, such asthe BAT54C diode manufactured by FAIRCHILD SEMICONDUCTOR of SouthPortland, Me., diode 780 may be a different Schottky diode, such as theCMS04 diode manufactured by TOSHIBA CORPORATION of Tokyo, Japan, andtransistors 710, 720, and 730 may be field effect transistors such asthe ZXMP3A13F transistor manufactured by ZETEX SEMICONDUCTOR ofManchester, England.

The line labeled Vcc_Vout_FW coming from transistor 720 may represent apower input to the electronic device coming from the second battery,which occurs, in certain embodiments, when rechargeable battery pack 100is in the second condition. The line labeled Vcc_Vout_FW coming fromtransistor 710 may represent a power input to the electronic device, forexample, coming from the external power source, which occurs, in someembodiments, when rechargeable battery pack 100 is in the firstcondition.

In some embodiments, transistors 720 and 730 (illustrated in FIG. 7 c)may be off when rechargeable battery pack 100 is in the first condition,and may be on when rechargeable battery pack 100 is in the secondcondition. Continuing the same example, transistor 710 may be on whenrechargeable battery pack 100 is in the first condition, and off whenrechargeable battery pack 100 is in the second condition. In thisembodiment, when the external power source is disconnected fromrechargeable battery pack 100 (after earlier being connected), capacitor755 will slowly discharge, eventually turning on transistor 720 andallowing the electronic device to receive power from the second battery.During this condition, transistor 730 may be on, and resistor 740 may bedetectable by the electronic device. In this embodiment, when theelectronic device detects resistor 740, the electronic device reacts bydrawing power from the second battery, and by ceasing any charging ofthe first battery. When rechargeable battery pack 100 is electricallycoupled to the external power source, transistors 720 and 730 may turnoff, and transistor 710 may slowly turn on, thus causing the electronicdevice to re-check ACC line 790, since power has been removed for ashort period of time. In certain embodiments, with transistor 730 turnedoff, resistor 740 cannot be detected by the electronic device, and theelectronic device will thus be permitted to charge the first batteryusing power from the external power source.

FIG. 8 is a circuit diagram showing a boost supply circuit 800 that isan example of such a circuit that may be included in some embodiments ofthe invention. Boost supply circuit 800 is a boost (or Step-Up)switching regulator. The voltage of the second battery may be boosted toa voltage in the range of the FireWire Specification, for example. Inone embodiment, that voltage is approximately 9.3 volts. Chip 801 may bemade by LINEAR TECHNOLOGY of Milpitas, Calif. The boost may be enabledonly when connected to an electronic device, such as an iPod™ device,and the VCC_(—)9V is not present (i.e. the electronic device is notconnected to an external power source). The dock connector of the iPod™device, for example, may have multiple ground pins, all of which may beconnected internally to the iPod™ device. One of these ground pins maybe used to detect when the iPod™ device is connected in order to enablethe boost supply. Whenever VCC_(—)9V is present, the boost supply may bedisabled, which may be independent of whether the iPod™ device isconnected. In some embodiments, switches may be used to enable/disablethe boost supply based on the above criteria.

Referring back to FIGS. 1 and 2, in the embodiment illustrated, body 110comprises a gas gauge or charge level indicator 130, which in someembodiments includes an actuator button 131, a light pipe 132, and, notexplicitly illustrated in the figures, first and second light sourcesinside body 110. In particular embodiments, charge level indicator 130gives a visual approximation of the charge remaining in rechargeablebattery pack 100, or of the approximate time remaining untilrechargeable battery pack 100 can no longer supply sufficient electricpower to operate the electronic device. In this particular embodiment,to operate charge level indicator 130, actuator button 131 is actuated,which, depending on the remaining charge level or time, causes one orboth of the first and second light sources to illuminate. In oneembodiment, actuator button 131, when actuated, causes one or both ofthe first and second light sources to stay lit for a limited period oftime, such as, for example, three seconds.

In one embodiment, actuator button 131 sets in motion a chain of eventsthat eventually cause: (1) the green light source to illuminate when aremaining charge level of rechargeable battery pack 100 exceeds a firstcharge level; (2) the red light source to illuminate when the remainingcharge level of rechargeable battery pack 100 is less than a secondcharge level; and (3) both the green light source and the red lightsource to illuminate, such that the green light source and the red lightsource emit light at the same time, when the remaining charge level ofrechargeable battery pack 100 is equal to or less than the first chargelevel and is also equal to or greater than the second charge level. Insome embodiments, the mixture of the green light and the red lightcreates light of a whitened yellowish orange color that will be referredto herein as amber. More specifically, in some embodiments, actuatorbutton 131 activates a circuit inside rechargeable battery pack 100 thatdetermines the remaining charge level of rechargeable battery pack 100and then causes either or both of the green light and the red lightsource to illuminate as described.

As an example, the first charge level may be defined as 75 percent offull charge, and the second charge level may be defined as 25 percent offull charge. In this example, a green light and a red light indicate,respectively, a relatively high and a relatively low remaining chargelevel, while an amber light indicates a remaining charge level somewherein between. It should be understood that in some embodiments, the firstand second charge levels may alternatively be defined as percentages offull charge other than the percentages given in the foregoing example,may be defined in terms of approximate time remaining until rechargeablebattery pack 100 is no longer able to supply sufficient power to operatean electronic device.

Recall from above that the battery inside rechargeable battery pack 100is referred to from time to time herein as the second battery. Thesecond battery may be a lithium-ion battery, for example. In certainembodiments, the second battery comprises two lithium-ion batterieselectrically connected in series. In some embodiments, in order toprevent damage to rechargeable battery pack 100, or to the secondbattery, the second battery is turned off or disconnected from beingdrained or used as a power source when the charge level of the secondbattery reaches a certain minimum threshold level, which will bereferred to as a first threshold level. The first threshold level may bemeasured as a voltage across the terminals of the second battery, forinstance. In one embodiment, the first threshold level is approximately5.4 volts, but in other embodiments different first threshold levels maybe used. In particular embodiments, the second battery is not turned onto be drained or used as a power source, once it has been turned off,until after a charge voltage is applied to the second battery, forexample, from an external power source. In other embodiments, the secondbattery is not turned on to be drained or used as a power source, onceit has been turned off, until after the charge level reaches a secondthreshold level that is higher than the first threshold level.

Further, in certain embodiments, the charge current to the secondbattery may be turned off or stopped once the second battery is fullycharged. In particular embodiments, for example, the second battery willbe charged, either fast or trickle, until a third threshold level isreached. This third threshold may be, for example, 8.4 volts, in certainembodiments, which may be measured across the terminals of the secondbattery, for example. In other embodiments, different threshold levelsmay be used. In some embodiments, a constant voltage may be applied asthe second battery is being charged, during at least part of thecharging cycle, and the charging rate of the second battery maygradually decrease as the voltage of the second battery approaches thisconstant voltage. In such embodiments, the constant voltage may be thethird threshold level, for example.

In one embodiment, the first and second light sources emit light at aconstant intensity whenever they are actuated. In another embodiment,the light sources are capable of emitting light at variable intensity.As a first example of the variable intensity embodiment, the lightsources may be capable of emitting light at discrete intensity levels,such as at full intensity, half intensity, and zero intensity. Thevisual result in this first example is very similar to that describedabove. As a second example of the variable intensity embodiment, thelight sources may be capable of emitting light in a continuous range ofintensity levels, such that the intensity of light emitted by the lightsources changes smoothly across the entire range from full intensity tozero intensity. In this second example, as the remaining charge level inrechargeable battery pack 100 changes from full to zero, the light seenthrough light pipe 132 changes smoothly along a continuum from brightgreen, through yellow-green, amber, and reddish-amber, and finally tored. A more accurate indication of the remaining charge level may bepossible in this second example, due to the greater number of lightintensities used. In a particular embodiment, less than 20 minutes mayremain when the light is fully red. If battery pack 100 is to be storedfor a long time without being used, in embodiments where the secondbattery is a lithium-ion battery, a reduction of capacity may be avoidedby storing battery pack 100 when charge level indicator 131 is red. Lossof capacity may further be avoided, in particular embodiments, bycharging battery pack 100 for 10 to 15 minutes every six months duringlong-term storage.

FIG. 9 is a circuit diagram illustrating an LED gas gauge circuit 900according to an embodiment of the invention. Circuit 900 may providefunctionality for charge level indicator 130 illustrated in FIGS. 1 and2, for example. In some embodiments, the LEDs are illuminated in thefollowing two scenarios: (1) actuator button 131 is actuated; or (2) thesecond battery is being charged. When actuator button 131 is actuated,the LED circuit may, in the embodiment illustrated, be powered for atime determined by the time constant produced by resistor 915 andcapacitor 909. The LED circuit may also be powered when rechargeablebattery pack 100 is plugged into an external power source. In this case,in a particular embodiment, the LEDs may be controlled by pin 14 of chip690 (FIG. 6), only illuminating when one of the above two scenariosexists. In this embodiment, pin 14 is connected to the LED shown in FIG.6. In some embodiments, when the second battery is fully charged, chip690 may turn off the LEDs. In some embodiments, the LEDs may turn offwhen the second battery has been charged to approximately 90%, and theuser may leave the battery pack 100 connected for 10 additional minutes,for example, after the LED turns off, to maximize the charge. But inthese embodiments, disconnecting battery pack 100 from the power supplysooner, or leaving it connected, may not damage battery pack 100. Insome embodiments, the LED may flash to indicate a fault. The user may beinstructed to disconnect the external power supply for 30 seconds, forexample, when the LED flashes.

An op-amp, voltage reference, and two transistors control the variableintensity of the red and green LEDs in one particular embodiment. Thereare various other ways to produce the effect of a gas gauge, which maybe utilized in particular embodiments of the invention, and circuit 900can be attained in various different ways. Further, the voltagethresholds can be set through changing the values of the resistors.

FIG. 10 is a diagram illustrating an example of the connections to dockconnector 240, to a battery terminal, and to a DC input jack onrechargeable battery pack 100 according to an embodiment of theinvention. In FIG. 10, the top block may represent connections to aniPod dock connector, for example. The middle block may represent batteryterminal connections. And the bottom block may illustrate DC input jackconnections, for example, which may include a resistor having aresistance of 1 K ohms and a capacitor having a capacitance of 10 microFarads in one embodiment.

In some embodiments, the DC input jack is on top of battery pack 100,for example, as shown in FIG. 1. The user may plug a DC pug end of apower cable (not shown) into the DC jack to charge battery pack 100, ormay connect a Firewire, for example, from an AC wall charger. Such aFirewire may be provided with the electronic device, or may be from aport on a laptop or desktop computer, for example. As described herein,the first battery and second battery may be charged simultaneously insome embodiments, and the first battery may continue to charge after thesecond battery is fully charged. In particular embodiments, it may takeabout 2 hours to charge the first battery second battery, or both, witha fast charge. Some embodiments, such as an iPod™ mini device, may takeonly one hour. In some embodiments it may take 4 hours for a fullcharge. The fast charge may provide 80% of a full charge, as an example.The user may disconnect battery pack 100 from the electronic device, forexample, at dock connector 240, or may turn off the electronic devicewhen the electronic device is not in use to conserve the charge ofbattery pack 100 or the second battery.

FIG. 10 further illustrates an example of a disconnectable electricalconnection that in some embodiments may be present between a device suchas rechargeable battery pack 100, and an electronic device, such as aportable electronic device, which, in some embodiments, may have abattery, may be configured to play audio recordings, or both, orspecifically, may be an MP3 player. As mentioned above, such anelectrical connection may be located inside an extension, which mayprotect the connection from damage.

FIG. 11 illustrates an example of a method in accordance with theinvention, method 1100, which includes manufacturing a power supplysystem or device such as a battery pack. A power supply system may becapable of providing electric power to an electronic device, which mayhave a (first) battery. Method 1100 may include, in some embodiments,not necessarily in the order presented herein, at least the steps ofproviding a body (step 1105) and providing a battery (step 1110), forexample, the second battery described herein, which may be locatedwithin the body. Various methods may also include providing anattachment apparatus (step 1115), which, in some embodiments, may beconfigured to at least partially surround and attach to the battery packand the electronic device. Method 1100 may also include the step ofproviding an electrical connector (step 1120), which may be configuredto electrically connect the battery pack and the electronic device. Insome embodiments, the step of providing an attachment apparatus (step1105) includes providing an extension projecting from the attachmentapparatus and configured to at least partially surround and protect theelectrical connector.

In particular embodiments, method 1100 may include the step of providingat least one circuit located within the body and configured to performat least one of a number of functions. Such functions may include, forexample, powering the electronic device from the second battery (step1125), which may take place when the battery pack is connected to theelectronic device and no external power source is connected to thebattery pack, for example. Another function that may be performed by acircuit that is provided, is to power the electronic device from anexternal power source (step 1130). In some embodiments, one or morecircuits may be provided that charge both the first battery and thesecond battery from the external power source when the battery pack isconnected to the electronic device and the external power source isconnected to the battery pack. In some embodiments, a circuit may beprovided that is configured to charge the second battery at one of atleast two non-zero rates of charge based on a power consumption level ofthe electronic device, for example. In such embodiments, the power maybe provided by the external power source, for instance. Method 1100 mayfurther include, in various embodiments, the step of providing a chargelevel indicator (step 1135), for example, on the battery pack.

The various components provided in method 1100 may be similar oridentical to the various components described herein. Thus, thecomponents described in detail herein may serve as examples of certainembodiments of the components provided in method 1100. In differentembodiments, steps 1105 through 1135 may be performed in a differentsequence than what is illustrated.

Once the various components are provided, the system or device may beassembled (step 1140), which may include various activities that wouldbe familiar to a person of ordinary skill in the art. In certainspecific embodiments, various methods in accordance with the inventionmay further include the step of marketing the power supply system (step1145). The battery pack, attachment apparatus, or both, may be marketedfor use with an electronic device, for instance, configured to playrecordings, or specifically, for use with an MP3 player, such as aniPod™ device. Marketing may include advertising, packaging, displayingin retail outlets, and the like.

Although the invention has been described with reference to specificembodiments, it will be understood by those skilled in the art thatvarious changes may be made to certain embodiments without departingfrom the spirit or scope of the invention. Various examples of suchchanges have been given in the foregoing description. Accordingly, thedisclosure of embodiments of the invention is intended to beillustrative of the scope of the invention and is not intended to belimiting. It is intended that the scope of the invention shall belimited only to the extent required by the appended claims. For example,to one of ordinary skill in the art, it will be readily apparent thatthe rechargeable battery pack and the attachment apparatus discussedherein may be implemented in a variety of embodiments, and that theforegoing discussion of certain of these embodiments does notnecessarily represent a complete description of all possibleembodiments.

All elements claimed in any particular claim are essential to theinvention claimed in that particular claim. Consequently, replacement ofone or more claimed elements constitutes reconstruction and not repair.Additionally, benefits, other advantages, and solutions to problems havebeen described with regard to specific embodiments. The benefits,advantages, solutions to problems, and any element or elements that maycause any benefit, advantage, or solution to occur or become morepronounced, however, are not to be construed as critical, required, oressential features or elements of any or all of the claims.

Moreover, embodiments and limitations disclosed herein are not dedicatedto the public under the doctrine of dedication if the embodiments and/orlimitations: (1) are not expressly claimed in the claims; and (2) are orare potentially equivalents of express elements and/or limitations inthe claims under the doctrine of equivalents.

1. A rechargeable battery pack configured to power an electronic devicehaving a first battery, the rechargeable battery pack comprising: asecond battery; an external power input port configured to couple to anexternal power source; a power output port for powering the electronicdevice; and a first circuit comprising: a first power path between theexternal power input port and the power output port of the rechargeablebattery pack; a second power path between the second battery and thepower output port of the rechargeable battery pack; and a power switchset; wherein: the first circuit is internal to the rechargeable batterypack; the rechargeable battery pack, along with its second battery,external power input port, power output port, and first circuit, isexternal to and distinct from the electronic device; the second batteryof the rechargeable battery pack is supplemental to the first battery ofthe electronic device; if the external power source is not coupled tothe external power input port of the rechargeable battery pack: thefirst power path is disabled by the power switch set; and the secondpower path is enabled by the power switch set; and if the external powersource is coupled to the external power input port of the rechargeablebattery pack: the first power path is enabled by the power switch set;and the second power path is disabled by the power switch set.
 2. Therechargeable battery pack of claim 1, further comprising: anidentification path configured to indicate a presence of therechargeable battery pack to the electronic device; and anidentification switch coupled to the identification path; wherein: theidentification switch is internal to the rechargeable battery pack; theidentification switch is distinct from the power switch set; when theexternal power source is decoupled from the external power input port ofthe rechargeable battery pack: the identification path is enabled forthe electronic device by the identification switch; and when theexternal power source is coupled to the external power input port of therechargeable battery pack: the identification path is disabled for theelectronic device by the identification switch.
 3. The rechargeablebattery pack of claim 2, wherein: the identification path comprises aresistance; and the resistance is detectable by the electronic device,as indicative of the presence of the rechargeable battery pack, when theidentification path is enabled by the identification switch.
 4. Therechargeable battery pack of claim 2, wherein: the identification switchcomprises: a control terminal coupled to the external power source; asecond terminal coupled to a first portion of the identification path;and a third terminal coupled to a second portion of the identificationpath; the resistance is located at the first portion of theidentification path between the second terminal of the identificationswitch and a ground path; when the identification path is enabled, thefirst and second portions of the identification path are coupledtogether by the identification switch; and when the identification pathis disabled, the first and second portions of the identification pathare decoupled from each other by the identification switch.
 5. Therechargeable battery pack of claim 1, wherein: the power switch setcomprises a switch having: a first terminal coupled to the power outputport; a second terminal coupled to the external power input port; and acontrol terminal coupled to the external power input port.
 6. Therechargeable battery pack of claim 5, wherein: when the external powerinput port is coupled to the external power source, the control terminalof the switch is actuated to couple the external power input port to thepower output port and thereby enable the first power path.
 7. Therechargeable battery pack of claim 5, wherein: the first circuitcomprises at least two of: a capacitor coupled between the controlterminal of the switch and the external power input port; a resistorcoupled between the control terminal of the switch and a ground path; ora diode coupled between the second terminal of the switch and theexternal power input port.
 8. The rechargeable battery pack of claim 1,further comprising: the power switch set comprises a switch having: afirst terminal coupled to the power output port; a second terminalcoupled to the second battery; and a control terminal coupled to theexternal power input port.
 9. The rechargeable battery pack of claim 8,wherein: when the external power input port is decoupled to the externalpower source, the control terminal of the switch is actuated to couplethe second battery to the power output port and thereby enable thesecond power path.
 10. The rechargeable battery pack of claim 8,wherein: the first circuit comprises at least two of: a resistor coupledbetween a first node and a ground path, the first node coupled to theexternal power input port; a capacitor coupled between the first nodeand the ground path; or one or more diodes coupled between the externalpower input port and the first node; the first node being coupled to thecontrol terminal of the switch.
 11. The rechargeable battery pack ofclaim 1, further comprising: a switching regulator coupled between thesecond battery and the second power path.
 12. The rechargeable batterypack of claim 1, further comprising: a body comprising: the secondbattery; and the power output port; wherein the external power inputport and the power output port are accessible via one or more walls ofthe body.
 13. The rechargeable battery pack of claim 1, furthercomprising: a second circuit configured to: charge the second batterywith a charge current from the external power source; and toggle thecharge current for the second battery between at least two non-zeromagnitudes based on a power consumption level of the electronic device.14. The rechargeable battery pack of claim 1, wherein: the power switchset comprises: a first switch having: a first terminal coupled to thepower output port; a second terminal coupled to the external power inputport; and a control terminal controlled by the external power inputport; and a second switch having: a first terminal coupled to the poweroutput port; a second terminal coupled to the second battery; and acontrol terminal controlled by the external power input port; wherein:when the external power input port is coupled to the external powersource: the control terminal of the first switch is actuated to couplethe external power input port to the power output port and therebyenable the first power path; and the control terminal of the secondswitch is deactuated to decouple the second battery from the poweroutput port and thereby disable the second power path; and when theexternal power input port is decoupled to the external power source: thecontrol terminal of the first switch is deactuated to decouple theexternal power input port from the power output port and thereby disablethe first power path; and the control terminal of the second switch isactuated to couple the second battery to the power output port andthereby enable the second power path.
 15. The rechargeable battery packof claim 1, further comprising: an attachment apparatus configured to atleast partially surround and attach to: a body of the rechargeablebattery pack; and the electronic device; an electrical connectorconfigured to electrically connect the rechargeable battery pack to theelectronic device; and an extension projecting from the attachmentapparatus and configured to at least partially surround and protect theelectrical connector.
 16. A method for providing a rechargeable batterypack configured to power an electronic device having a first battery,the method comprising: providing a second battery supplemental to thefirst battery; providing an external power input port configured tocouple to an external power source; providing a power output port forpowering the electronic device; providing a first circuit comprising: afirst power path between the external power input port and the poweroutput port of the rechargeable battery pack; a second power pathbetween the second battery and the power output port of the rechargeablebattery pack; and a power switch set; and providing a body of therechargeable battery pack, the body comprising: the second battery, theexternal power input port, the power output port, and the first circuit;wherein: the rechargeable battery pack and the body are external to theelectronic device; and providing the first circuit comprises: providingthe power switch set to both enable the second power path and disablethe first power path if the external power source is not coupled to theexternal power input port of the rechargeable battery pack; andproviding the power switch set to both enable the first power path anddisable the second power path if the external power source is coupled tothe external power input port of the rechargeable battery pack.
 17. Themethod of claim 16, further comprising: providing an identificationswitch coupled along an identification path for the electronic device;wherein: the identification switch is internal to the rechargeablebattery pack; the identification switch is distinct from the powerswitch set; the identification switch enables the identification path,when the external power source is decoupled from the external powerinput port of the rechargeable battery pack, to permit the electronicdevice to detect a resistance indicative of the presence of therechargeable battery pack; and the identification switch disables theidentification path when the external power source is coupled to theexternal power input port of the rechargeable battery pack.
 18. Themethod of claim 16, wherein: providing the first circuit comprises:providing a switch of the power switch set to comprise: a first terminalcoupled to the power output port; a second terminal coupled to theexternal power input port; and a control terminal coupled to theexternal power input port; and providing the switch to enable the firstpower path, when the external power input port is coupled to theexternal power source, by coupling the external power input port to thepower output port.
 19. The method of claim 16, wherein: providing thefirst circuit comprises: providing a switch of the power switch set tocomprise: a first terminal coupled to the power output port; a secondterminal coupled to the second battery; and a control terminal coupledto the external power input port; and providing the switch to enable thesecond power path, when the external power input port is decoupled formthe external power source, by coupling the second battery to the poweroutput port.
 20. The method of claim 16, wherein: providing a secondcircuit configured to: charge the second battery with a charge currentfrom the external power source; and toggle the charge current for thesecond battery between at least two non-zero magnitudes based on a powerconsumption level of the electronic device.
 21. A rechargeable batterypack configured to power an electronic device having a first battery,the rechargeable battery pack comprising: a second battery supplementalto the first battery when the first battery is coupled to the electronicdevice; and a first circuit coupled to the second battery and configuredto dynamically change a charge current supplied from an external powersource to the second battery based on a power consumption level of theelectronic device; wherein: the first circuit is internal to therechargeable battery pack; the rechargeable battery pack, along with itssecond battery, and first circuit, is external to and distinct from theelectronic device; the charge current comprises a first portion and asecond portion less than the first portion; the first circuit comprises:a current sense subcircuit configured to measure a power consumptionlevel of the electronic device; a switch having a first terminalelectrically coupled to an output of the current sense subcircuit; afirst path coupled to a second terminal of the switch and configured totransmit the first portion of the charge current to the second battery;and a second path configured to transmit the second portion of thecharge current to the second battery when the external power source iscoupled to the first circuit; when the power consumption level isgreater than a second level: the switch is disabled via the output ofthe current sense subcircuit to restrict a transmission of the firstportion of the charge current via the first path; and when the powerconsumption level is less than a first level: the switch is enabled viathe output of the current sense subcircuit; and the first portion of thecharge current is transmitted to the second battery via the first path.22. The rechargeable battery pack of claim 21, wherein: the second levelof the power consumption is greater than the first level of the powerconsumption.
 23. The rechargeable battery pack of claim 21, wherein: thefirst and second levels of the power consumption are substantially equalto each other.
 24. The rechargeable battery pack of claim 21, furthercomprising: a second circuit configured to: power the electronic devicewith the second battery when the rechargeable battery pack is decoupledfrom the external power source; and power the electronic device with theexternal power source when the rechargeable battery pack is coupled tothe external power source.
 25. The method of claim 17, wherein:providing the identification switch comprises: providing a controlterminal configured to couple to the external power source; providing asecond terminal coupled to a first portion of the identification path;and providing a third terminal coupled to a second portion of theidentification path; the resistance is located at the first portion ofthe identification path between the second terminal of theidentification switch and a ground path; when the identification path isenabled, the first and second portions of the identification path arecoupled together by the identification switch; and when theidentification path is disabled, the first and second portions of theidentification path are decoupled from each other by the identificationswitch.
 26. The method of claim 18, wherein: providing the first circuitcomprises: providing at least two of: a capacitor coupled between thecontrol terminal of the switch and the external power input port; aresistor coupled between the control terminal of the switch and a groundpath; or a diode coupled between the second terminal of the switch andthe external power input port.
 27. The method of claim 19, wherein:providing the first circuit comprises: providing at least two of: aresistor coupled between a first node and a ground path, the first nodecoupled to the external power input port; a capacitor coupled betweenthe first node and the ground path; or one or more diodes coupledbetween the external power input port and the first node; the first nodebeing coupled to the control terminal of the switch.